React native: Gradle android version strategy (android/app/build.gradle)

build.gradle

import groovy.json.JsonSlurper
def getNpmVersion() {
    def inputFile = new File("../package.json")
    def packageJson = new JsonSlurper().parseText(inputFile.text)
    return packageJson["version"]
}
def getCommitTime() {
    return (Integer) (Long.valueOf('git log -1 --pretty=format:%ct'.execute().getText().trim())/3600)
}

ext {
    _VERSION_NAME = getNpmVersion()
    _VERSION_CODE = System.getenv("BUILD_NUMBER") as Integer ?: getCommitTime()
}

afterEvaluate {
    println '****************************************'
    println 'Version Name: ' + _VERSION_NAME
    println 'Version Code: ' + _VERSION_CODE
    println '****************************************'
}